driveshaft difference? convertible or not?

[papajetta]

i am doing a 5 speed conversion on a 91 vert. i am trying to get the driveshaft but its asking weather its a vert or not?
now thats 3 different driveshafts.
reg auto , reg manual, and now a vert drive shaft
does anyone know which one a have to go with? or whats the difference between the 3? or are there really 4 choices